1. Field of the Invention
The present invention relates to a wired circuit board, to be specific, to a wired circuit board that is preferably used as a suspension board with circuit.
2. Description of Related Art
In a wired circuit board that is used in an electronic/electrical device and the like, a terminal portion so as to be connected to an external terminal is usually formed.
In recent years, as the terminal portion, in order to respond to high density growth and miniaturization of the electronic/electrical device, a so-called flying lead that is formed not only on one surface of a conductive pattern, but also on both surfaces thereof has been becoming common. For example, it has been known that in a suspension board with circuit and the like that is used in a hard disk drive, the terminal portion is formed as the flying lead.
For example, it has been disclosed that in the suspension board with circuit including a supporting board, a base layer that is formed on the supporting board, a conductive pattern that is formed on the base layer as a predetermined wired circuit pattern, and a cover layer covering the conductive pattern, the cover layer is formed to have an opening to expose the top surface of the conductive pattern, and the supporting board and the base layer are formed to have an opening to expose the back surface of the conductive pattern, so that the exposed conductive pattern is defined as the flying lead.
Then, for example, by using a bonding tool and the like, the flying lead is connected to an external terminal by applying ultrasonic vibration thereto (ref: for example, Japanese Unexamined Patent Publication No. 2003-31915).